<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="abc">
        <div class="b">123</div>
    </div>

    <script src="../lib/jquery.min.js"></script>
    <script>
        // 获取jq元素
        console.log($('#abc'));
        // 获取文字
        console.log($('#abc').text());
        // 获取结构
        console.log($('#abc').html());
        // 获取宽高
        console.log($('#abc').width());
        console.log($('#abc').height());

        // document.querySelector('#abc').innerHTML = '';
        // $('#abc').html('');
        // 把div.b的文字设置为hello world
        $('.b').text('hello world');

    </script>
</body>
</html>